Electrical and structural properties of rapidly annealed rare-earth metal Er Schottky contacts on p-type InP

We investigate the effect of annealing temperature on the electrical and structural properties of Er/p-InP Schottky contacts. The barrier height of as-deposited Er Schottky contacts is found to be 0.89 eV (I-V) and 0.98 eV (C-V). After annealing at 200 C, a maximum barrier height is obtained for the Er Schottky contact and the corresponding values are 0.93 eV (I-V) and 1.11 eV (C-V). However, both I-V and C-V measurements show that the barrier height slightly decreases for the contacts annealed at 300 C and 400 C. Norde and Cheung's methods are used to extract the barrier height, ideality factor, and series resistance of Er/p-InP Schottky contact. The barrier heights obtained from the Norde and Cheung's methods are closely matched with those obtained from the I-V method. Further, the discrepancy between Schottky barrier heights calculated from I-V and C-V methods is also discussed. Based on the AES and XRD results, the increase or decrease in Schottky barrier heights upon annealing at elevated temperatures could be attributed to the formation of interfacial phases at the Er/p-InP interface vicinity.